Abstract:
Landslides pose a significant threat to infrastructure, property, and human lives in many regions
worldwide, including Chira town in Ethiopia. This study presents an integrated geotechnical and
geophysical investigation aimed at identifying the contributing factors to landslides in Chira
town, Ethiopia, with a focus on a recent landslide event. The methodology employed a combi nation of geotechnical and geophysical techniques to comprehensively analyze the landslide
problem. The geotechnical investigation involved a detailed analysis of the soil characteristics in
the area, including the composition of fine-grained soil and the determination of cohesion and
angle of internal friction through triaxial testing. The geophysical investigation utilized electrical
resistivity tomography to assess the subsurface soil profile. The findings revealed the presence of a
massive basaltic tertiary volcanic rock layer underlying a very low resistivity layer of sticky clay
soil. Through this study, it was established that rainfall, soil type, land use, elevation, and
proximity to streams, slopes, and aspects were the main factors contributing to the landslide,
accounting for 22.03%, 18.89%, 15.75%, 15.46%, 10.87%, 9.7%, and 7.5% of the overall in fluence, respectively. Based on these findings, the study proposes a range of interventions to
enhance resilience against landslides, including surface drainage, the implementation of appro priate land use management practices, and the introduction of vetiver vegetation. The integration
of geotechnical and geophysical methodologies provided a comprehensive understanding of the
landslide problem in Chira town. The proposed interventions aim to inform future land use
planning, infrastructure development, and disaster risk reduction efforts in the region. By
expanding our knowledge of the mechanisms driving landslides, this study offers valuable in sights that can be utilized in similar regions facing comparable geotechnical and geophysical
conditions.
